G-protein coupled receptors (GPCRs) are an essential family of proteins on the cell membrane, widely distributed in various types of tissues and cells. Typical GPCRs are composed of characteristic 7 transmembraneα-helix domains, extracellular domain and intracellular domain. They play a key role in transmitting information inside and outside cells. These receptors can sense and respond to a variety of external signals, including odor molecules, hormones, neurotransmitters, chemokines, and so on, thereby regulating the physiological functions and metabolic activities of cells. When external signal molecules bind, these receptors undergo conformational changes, thereby activating signal transduction pathways inside cells. The most common downstream signal pathway is the activation of G proteins, but it may also activate the β-arrestin signaling pathway. This series of signal transduction processes ultimately regulates physiological processes such as cell metabolism, proliferation, and differentiation, and also plays an important role in the occurrence and development of diseases. Due to its importance in regulating cell functions and participating in the development of diseases, GPCRs have become important targets in the field of drug research and development. The mechanism of action of many drugs is achieved by intervening in the GPCR signaling pathway. As important form of function regulating, dimerization has attracted widespread attention in the research of GPCR field. In the early days, the formation of GPCR dimerization and its effect on receptor function were mainly studied by immunoprecipitation, immunofluorescence and radioligand binding experiments in overexpression systems. Nowadays, with the continuous development of biochemical and biophysical methods, more and more GPCR dimers have been identified. GPCR dimer refers to the process in which two GPCR subunits bind to each other to form a complex. The same GPCR subunits form homodimers, and different GPCR subunits form heterodimers through direct interaction. Dimerization changes the activity, affinity, internalization, localization and transport, and signal transduction characteristics of GPCR, thereby producing more complex and delicate regulation of cellular physiological processes. In recent years, the research on GPCR dimers has been continuously deepened, revealing its important role in a variety of physiological and pathological processes. In general, the structure of GPCR dimers is complex and diverse, and its formation and stability are affected by many factors, including the specificity of receptor interaction interface, the conformational changes of receptor, and the regulation of intracellular and extracellular environment. By understanding the mechanism of GPCR dimerization, we can better understand the behavior of these receptors in signal transduction and provide new ideas and opportunities for the development of novel drug targets. More and more studies have reported the dimerization of GPCR and its structure and function regulation mechanism. This article reviews the research progress on the structure and function of GPCR dimers, and summarizes some research methods and technologies, which provide a basis for understanding the discovery of GPCR dimers, dimerization methods, structure and function regulation mechanisms, and further targeting GPCR dimers. It provides a research basis for the development of polymer drugs.

Depression is a prevalent mental illness worldwide, its multifaceted pathogenesis is still in the exploratory stage. MicroRNA (miRNA), as a crucial epigenetic regulator, plays an important role in depression. miR-124 is one of the most abundant miRNAs in the central nervous system including neurons and microglia, and involved in various biological events like neuron development and differentiation, synaptic and axonal growth, neural plasticity, inflammation and autophagy. Recent studies have reported abnormal expression of miR-124 in both depression patients and animal models. Most of the studies showed that miR-124 is upregulated in the hippocampus or prefrontal cortex in stress-induced rodent depression animal models such as CUMS, CSDS, CORT, CRS and LH but some evidence for divergence. Upregulation of miR-124 expression may be involved in depression-like behavior via CREB/BDNF/TrkB pathway, GR pathway, SIRT1 pathway, apoptosis and autophagy pathways by directly targeting these genes including Creb, Bdnf, Sirt1, Nr3c1, Ezh2 and Stat3. The downregulation of miR-124 expression in neurons is mainly involved in the neurogenesis and neuroplasticity impairments in depression by targeting the Notch signaling pathway and DDIT4/TSC1/2/mTORC1 pathway. The downregulation of miR-124 expression also was found in the activated microglia in the stress-induced models, and resulted in neuroinflammation. In summary, the abnormal expression of miR-124 in the brain of depression-related models and its related mechanisms are complex and even contradictory, and still need further research. This review provides a summary of the research progress of miR-124 in depression.

Objective To investigate the clinical characteristics of Ureaplasma urealyticum(UU)infection and colonization in extremely preterm infants and its impact on the incidence of bronchopulmonary dysplasia(BPD).Methods A retrospective analysis was conducted on 258 extremely preterm infants who were admitted to the Department of Neonatology,Shenzhen Maternity and Child Healthcare Hospital,from September 2018 to September 2022.According to the results of UU nucleic acid testing and the evaluation criteria for UU infection and colonization,the subjects were divided into three groups:UU-negative group(155 infants),UU infection group(70 infants),and UU colonization group(33 infants).The three groups were compared in terms of general information and primary and secondary clinical outcomes.Results Compared with the UU-negative group,the UU infection group had significant increases in the incidence rate of BPD,total oxygen supply time,and the length of hospital stay(P<0.05),while there were no significant differences in the incidence rates of BPD and moderate/severe BPD between the UU colonization group and the UU-negative group(P>0.05).Conclusions The impact of UU on the incidence of BPD in extremely preterm infants is associated with the pathogenic state of UU(i.e.,infection or colonization),and there are significant increases in the incidence rate of BPD,total oxygen supply time,and the length of hospital stay in extremely preterm infants with UU infection.UU colonization is not associated with the incidence of BPD and moderate/severe BPD in extremely preterm infants.

This study was aimed at investigating the effect of lymphocyte activation gene-3(LAG3)on liver B lymphocyte subsets and their functions in WT and LAG3-KO mice infected with Echinococcus multilocularis(E.multilocularis).In a mouse model of E.multilocularis infection,the expression and localization of CD19 and α-SMA in liver were detected by immu nohistochemistry.CD80,CD86 and MHC-Ⅱ molecules expressed on B cells and their subsets in mice liver were detected by flow cytometry.After 12 weeks of infection,the area and percentage of CD19 in LAG3-KO group was slightly higher than that in WT group,but the difference was not statistically(t=-1.241、-1.237,P＞0.05).The area and percentage of a-SMA in LAG3-KO group was higher than that in WT group(t=-3.224、-3.227,P＜0.05).The proportion of CD80 and MHC-Ⅱ molecules expressed on liver B cells in LAG3-KO group was up-regulated(t=-2.379,-3.321,P＜0.05).The percentage of liver B2 cells in LAG3-KO group was higher than that in WT group(t=-2.695,P＜0.05).The expression of CD80 on Blb cells in LAG3-KO group was significantly up-regulated(t=-5.315,P＜0.001).The proportion of CD80 of B2 cells in LAG3-KO group was lower than that in WT group(t=2.806,P＜0.05).The expression of MHC-Ⅱ molecule in B2 cells in LAG3-KO group was up-regulated(t=-4.227,P＜0.01).It is suggested that LAG3 molecules affected the B cell subsets and func-tion of mouse liver in the middle stage of E.multilocularis infection,especially B2 lymphocytes.LAG3 molecule exerted an in-hibitory effect on the activation of B cells and the expression of MHC-class Ⅱ molecules,suggesting that it may be involved in B cell exhaustion caused by E.multilocularis.

Conversion of 5-methylcytosine (5mC) to 5-hydroxymethylcytosine (5hmC) by ten-eleven translocation (TET) family proteins leads to the accumulation of 5hmC in the central nervous system; however, the role of 5hmC in the postnatal brain and how its levels and target genes are regulated by TETs remain elusive. We have generated mice that lack all three Tet genes specifically in postnatal excitatory neurons. These mice exhibit significantly reduced 5hmC levels, altered dendritic spine morphology within brain regions crucial for cognition, and substantially impaired spatial and associative memories. Transcriptome profiling combined with epigenetic mapping reveals that a subset of genes, which display changes in both 5hmC/5mC levels and expression patterns, are involved in synapse-related functions. Our findings provide insight into the role of postnatally accumulated 5hmC in the mouse brain and underscore the impact of 5hmC modification on the expression of genes essential for synapse development and function.
Animals ; Brain/growth & development* ; 5-Methylcytosine/metabolism* ; Mice ; Synapses/genetics* ; Proto-Oncogene Proteins/metabolism* ; DNA-Binding Proteins/metabolism* ; Dioxygenases/metabolism* ; Cognition/physiology* ; Gene Expression ; Mixed Function Oxygenases/metabolism* ; Epigenesis, Genetic ; Mice, Knockout ; Mice, Inbred C57BL

Objective: To analyze the clinical characteristics of children with multisystem inflammatory syndrome (MIS-C) associated with SARS-CoV-2 in China, and to improve the understanding of MIS-C among pediatricians. Methods: Case series study.Collect the clinical characteristics, auxiliary examinations, treatment decisions, and prognosis of 64 patients with MIS-C from 9 hospitals in China from December 2022 to June 2023. Results: Among the 64 MIS-C patients, 36 were boys and 28 were girls, with an onset age being 2.8 (0.3, 14.0) years. All patients suffered from fever, elevated inflammatory indicators, and multiple system involvement. Forty-three patients (67%) were involved in more than 3 systems simultaneously, including skin mucosa 60 cases (94%), blood system 52 cases (89%), circulatory system 54 cases (84%), digestive system 48 cases (75%), and nervous system 24 cases (37%). Common mucocutaneous lesions included rash 54 cases (84%) and conjunctival congestion and (or) lip flushing 45 cases (70%). Hematological abnormalities consisted of coagulation dysfunction 48 cases (75%), thrombocytopenia 9 cases (14%), and lymphopenia 8 cases (13%). Cardiovascular lesions mainly affected cardiac function, of which 11 patients (17%) were accompanied by hypotension or shock, and 7 patients (12%) had coronary artery dilatation.Thirty-six patients (56%) had gastrointestinal symptoms, 23 patients (36%) had neurological symptoms. Forty-five patients (70%) received the initial treatment of intravenous immunoglobulin in combination with glucocorticoids, 5 patients (8%) received the methylprednisolone pulse therapy and 2 patients (3%) treated with biological agents, 7 patients with coronary artery dilation all returned to normal within 6 months. Conclusions: MIS-C patients are mainly characterized by fever, high inflammatory response, and multiple organ damage. The preferred initial treatment is intravenous immunoglobulin combined with glucocorticoids. All patients have a good prognosis.
Male ; Child ; Female ; Humans ; Immunoglobulins, Intravenous/therapeutic use* ; Blood Coagulation ; COVID-19 ; China/epidemiology* ; Connective Tissue Diseases ; Coronary Aneurysm ; Fever ; Systemic Inflammatory Response Syndrome/therapy*

Krüppel-like transcription factor 2 (KLF2) plays a key regulatory role in endothelial inflammation, thrombosis, angiogenesis and macrophage inflammation and polarization, and up-regulation of KLF2 expression has the potential to prevent and treatment atherosclerosis. In this study, trichostatin C (TSC) was obtained from the secondary metabolites of rice fermentation of Streptomyces sp. CPCC 203909 as a KLF2 up-regulator by using a high throughput screening model based on a KLF2 promoter luciferase reporter assay. TSC significantly inhibited the adhesion of tumor necrosis factor-α (TNFα) induced monocytes (THP-1) to human umbilical vein endothelial cells (HUVECs). Western blot results showed that TSC decreased TNFα induced the protein expression increase of vascular cell adhesion molecule-1 (VCAM-1), and thereby inhibited endothelial inflammation. The results of histone deacetylase (HDAC) overexpression and molecular docking experiments showed that TSC upregulated the expression of KLF2 by inhibiting subtypes of HDAC 4/5/7. In conclusion, this study suggests that TSC up-regulates the expression of KLF2 through inhibiting HDAC 4/5/7 and thus inhibits TNFα induced endothelial inflammation, and it has the potential to prevent and treat atherosclerosis.

OBJECTIVE: To analyze the clinical data and genetic characteristics of a child with fibrocartilage hyperplasia type 1 (FBCG1). METHODS: A child who was admitted to Gansu Provincial Maternity and Child Health Care Hospital on January 21, 2021 due to severe pneumonia and suspected congenital genetic metabolic disorder was selected as the study subject. Clinical data of the child was collected, and genomic DNA was extracted from peripheral blood samples from the child and her parents. Whole exome sequencing (WES) was carried out, and candidate variants were verified by Sanger sequencing. RESULTS: The patient, a 1-month-old girl, had presented with facial dysmorphism, abnormal skeletal development, and clubbing of upper and lower limbs. WES revealed that she has harbored compound heterozygous variants c.3358G>A/c.2295+1G>A of the COL11A1 gene, which has been associated with fibrochondrogenesis. Sanger sequencing has verified that the variants have been respectively inherited from her father and mother, both of whom were phenotypically normal. Based on the guidelines from the American College of Medical Genetics and Genomics (ACMG), the c.3358G>A variant was graded as likely pathogenic (PM1+PM2_Supporting+PM3+PP3), and so was the c.2295+1G>A variant (PVS1＋PM2_Supporting). CONCLUSION The compound heterozygous variants c.3358G>A/c.2295+1G>A probably underlay the disease in this child. Above finding has facilitated definite diagnosis, genetic counseling for her family.
Female ; Humans ; Infant ; Abnormalities, Multiple ; Collagen Type XI/genetics* ; Genetic Counseling ; Genomics ; Mutation

Objective: To analyze the prevalence and the risk factors of fungal sepsis in 25 neonatal intensive care units (NICU) among preterm infants in China, and to provide a basis for preventive strategies of fungal sepsis. Methods: This was a second-analysis of the data from the "reduction of infection in neonatal intensive care units using the evidence-based practice for improving quality" study. The current status of fungal sepsis of the 24 731 preterm infants with the gestational age of <34⁺⁰ weeks, who were admitted to 25 participating NICU within 7 days of birth between May 2015 and April 2018 were retrospectively analyzed. These preterm infants were divided into the fungal sepsis group and the without fungal sepsis group according to whether they developed fungal sepsis to analyze the incidences and the microbiology of fungal sepsis. Chi-square test was used to compare the incidences of fungal sepsis in preterm infants with different gestational ages and birth weights and in different NICU. Multivariate Logistic regression analysis was used to study the outcomes of preterm infants with fungal sepsis, which were further compared with those of preterm infants without fungal sepsis. The 144 preterm infants in the fungal sepsis group were matched with 288 preterm infants in the non-fungal sepsis group by propensity score-matched method. Univariate and multivariate Logistic regression analysis were used to analyze the risk factors of fungal sepsis. Results: In all, 166 (0.7%) of the 24 731 preterm infants developed fungal sepsis, with the gestational age of (29.7±2.0) weeks and the birth weight of (1 300±293) g. The incidence of fungal sepsis increased with decreasing gestational age and birth weight (both P<0.001). The preterm infants with gestational age of <32 weeks accounted for 87.3% (145/166). The incidence of fungal sepsis was 1.0% (117/11 438) in very preterm infants and 2.0% (28/1 401) in extremely preterm infants, and was 1.3% (103/8 060) in very low birth weight infants and 1.7% (21/1 211) in extremely low birth weight infants, respectively. There was no fungal sepsis in 3 NICU, and the incidences in the other 22 NICU ranged from 0.7% (10/1 397) to 2.9% (21/724), with significant statistical difference (P<0.001). The pathogens were mainly Candida (150/166, 90.4%), including 59 cases of Candida albicans and 91 cases of non-Candida albicans, of which Candida parapsilosis was the most common (41 cases). Fungal sepsis was independently associated with increased risk of moderate to severe bronchopulmonary dysplasia (BPD) (adjusted OR 1.52, 95%CI 1.04-2.22, P=0.030) and severe retinopathy of prematurity (ROP) (adjusted OR 2.55, 95%CI 1.12-5.80, P=0.025). Previous broad spectrum antibiotics exposure (adjusted OR=2.50, 95%CI 1.50-4.17, P<0.001), prolonged use of central line (adjusted OR=1.05, 95%CI 1.03-1.08, P<0.001) and previous total parenteral nutrition (TPN) duration (adjusted OR=1.04, 95%CI 1.02-1.06, P<0.001) were all independently associated with increasing risk of fungal sepsis. Conclusions: Candida albicans and Candida parapsilosis are the main pathogens of fungal sepsis among preterm infants in Chinese NICU. Preterm infants with fungal sepsis are at increased risk of moderate to severe BPD and severe ROP. Previous broad spectrum antibiotics exposure, prolonged use of central line and prolonged duration of TPN will increase the risk of fungal sepsis. Ongoing initiatives are needed to reduce fungal sepsis based on these risk factors.
Infant ; Infant, Newborn ; Humans ; Birth Weight ; Intensive Care Units, Neonatal ; Retrospective Studies ; Tertiary Care Centers ; Infant, Extremely Low Birth Weight ; Gestational Age ; Infant, Extremely Premature ; Sepsis/epidemiology* ; Retinopathy of Prematurity/epidemiology* ; Bronchopulmonary Dysplasia/epidemiology*

OBJECTIVE: Exposure to high intensity, low frequency noise (HI-LFN) causes vibroacoustic disease (VAD), with memory deficit as a primary non-auditory symptomatic effect of VAD. However, the underlying mechanism of the memory deficit is unknown. This study aimed to characterize potential mechanisms involving morphological changes of neurons and nerve fibers in the hippocampus, after exposure to HI-LFN. METHODS: Adult wild-type and transient receptor potential vanilloid subtype 4 knockout (TRPV4^-/-) mice were used for construction of the HI-LFN injury model. The new object recognition task and the Morris water maze test were used to measure the memory of these animals. Hemoxylin and eosin and immunofluorescence staining were used to examine morphological changes of the hippocampus after exposure to HI-LFN. RESULTS: The expression of TRPV4 was significantly upregulated in the hippocampus after HI-LFN exposure. Furthermore, memory deficits correlated with lower densities of neurons and neurofilament-positive nerve fibers in the cornu ammonis 1 (CA1) and dentate gyrus (DG) hippocampal areas in wild-type mice. However, TRPV4^-/- mice showed better performance in memory tests and more integrated neurofilament-positive nerve fibers in the CA1 and DG areas after HI-LFN exposure. CONCLUSION TRPV4 up-regulation induced neurofilament positive nerve fiber injury in the hippocampus, which was a possible mechanism for memory impairment and cognitive decline resulting from HI-LFN exposure. Together, these results identified a promising therapeutic target for treating cognitive dysfunction in VAD patients.
Animals ; Mice ; TRPV Cation Channels/metabolism* ; Intermediate Filaments/metabolism* ; Hippocampus/metabolism* ; Neurons/metabolism* ; Memory Disorders/metabolism*